... is the basic element of bus bar system, may be mounted with 5mm or 10mm-length ... rectangular busbar, double-T Universal bus bar frame , , is used for bus bar of 12,15,20,25,3*5 ... ,2,30*5/10 Bottom groove , suitable for UL - bus bar framePE/E-bus bar frame, is used for 12,15,20,25 ...